What's wrong with these leaves? Variegated rubber plant.
As you can see from the photos below, the new leaves at the top look perfect. However, the older leaves have brown, dried edges at some of the leaf's periphery. I don't fertilize it much, maybe a couple times a year, sprinkle some Osmocote, water when I feel the soil is dry. I checked with my fingers, as well as when I see a gap developing between the soil and the wall of the pot. The plant sits at a west facing window.